The Dirty Rat Advanced 66cc Performance Bike Engine

Original price was: $399.99.Current price is: $369.99.

Out of stock

It looks like something you pulled out of your grandfather’s garage, but it isn’t anything less than FAST. Check out another one of Matt’s accidental creations… “The Dirty Rat” is a steam punked 66cc advanced race-ready performance engines that includes all the bells and whistles not found in your grandfather’s garage.

Out of stock

SKU: RATRCENG Categories: ,


The “Dirty Rat”? ? It ain’t pretty, but it’s pretty fast!?

This engine is our top of the line powerhouse.? We’ve sold over 500 of this series engine in the last 2 years since making them available to the public.? You get A LOT of engine for your money – you’d have to spend a lot more elsewhere to get anything even close to this kind of power.

The finish on this series is created by using chemical processes and a little bit of high-temp engine enamel.? Everything else on this engine is identical to our bare-aluminum Advanced Race Engine.


Here’s what this engine is all about;? I start with a 38mm stroke bottom end that is factory balanced to within perfection.? I make sure that the crank and the shaft are true, correcting it when needed.? I remove the small gear, magnet, sprocket and clutch from the shafts to ensure the keys are in properly and everything is true.? Loktite is used during reassembly.

Each cylinder is chosen carefully.? I use cylinders that have HUGE transfer ports, and I make a knife-edge on the entry wall for increased flow.? I also enlarge the port, reshape it, redirect the flow rearward, and smooth out all obstructions.? I then reshape and modify the intake and exhaust ports, and finish it all off with lowering the deck height to create optimal compression and proper squish clearance.

This engine Includes:

Very well-balanced bottom end from a single reliable source.

66cc Race-Ready GT5 Engine

Cylinder is decked for proper squish clearance and optimal compression.

Copper Head Gasket

USA Made Billet Aluminum High-Compression Head (6cc combustion chamber)

Ported cylinder for advanced timing

HUGE Transfer Ports with Knifed Edges.

Transfer Ports cleared, reshaped and redirected.

Piston ramped at the exhaust and skirt properly trimmed at intake.

Studs in cylinder replaced with grade 8.8 studs and hardware.

This engine will make you go FAST! The only thing more that you can do to increase your speed is to get a smaller rear sprocketor an advanced CDI and expansion chamber exhaust. I do not recommend adding a sprocket or new CDI unless you are a professional!

By bidding on or using ?Buy-it-Now? to purchase this engine you agree to the following statements:

I (the buyer) am 18 years of age or older.

This engine has no warrantee due to the power it produces, but I will offer you support along the way. Feel free to contact me about any questions you may have.

This engine is for racing only. Not for on-road use.

I (the buyer) am responsible for ANY damages or loss that occurs.

The seller of this engine is not responsible or liable for any direct or indirect damage or loss that the use of this or other products may cause.

This engine will make me (the buyer) go VERY FAST – a helmet and ALL OTHER safety equipment must be worn at all times.

I (the buyer) will use this product fully knowing & understanding that going fast on 2 wheels with a very fast gasoline engine attached is VERY DANGEROUS. I (the buyer) understand and accept that doing so may cause serious bodily harm or even death. I (the buyer) take full responsibility for using this engine in any way (intended or not intended.)

Additional information

Weight 25 lbs


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